Tab-stop setting device for business machines



July 26, 1960 H. L. LAMBERT 2,946,422

TAB-STOP SETTING DEVICE FOR BUSINESS MACHINES I Filed Oct. 23. 1959 Fig.

INVENTOR HARRY L. :AgRT BY gLML M WWW ATTORNEYS ilnired States;

TAB-STOP SETTING DEVICE FOR BUSINESS MACHINES Filed Oct. 23, 1959, Ser. No. 848,403

4 (Ilaims. ($1. 197-179) This invention relates to a novel tabulation stop setting device for business machines and the like, and more par ticularlyrelatesmto a novel'construction and arrange;- ment for the tab set blade for typewriters having proportional escapements for controlling the variable incremental letter feed movements of the carriage.

In the operation of present typewriters having proportional escapement devices the typewriter carriage may at any given time be in a position so that the usual tab stop setting blade is located between two adjacent tab stops. For this reason particular care must be taken to see that the carriage is properly positioned so that the tab setting blade and any tab stop that is to be set are substantially coplanar otherwise operation of the tab set mechanism will fail to properly displace the tab stop to its operative carriage arresting position. problem has heretofore required the typist to count incremental spaces, repeatedly operate the space bar and/ or intermittently operate the back space key of the typewriter during a tab setting operation.

One object of the present invention is to provide a simple inexpensive means for enabling the tab stop setting operations for proportional spacing typewriters to be carried out without requiring the machine operator to make calculations and without the necessity of said operator having to serially or simultaneously manipulate several of the typewriter carriage control linkages.

Another object of the invention is to provide a novel tab stop arrangement for proportional spacing typewriters whereby the tab stop setting member is provided with a laterally extending tab stop engaging head of predetermined width, said width being effectively less than the distance between two successive tab stops but at least as great as the combined length of that number of incremental units of carriage movement which is one less than the number of said units between two adjacent tab stops.

A further object of the invention is to provide a novel tab stop setting device for a proportional spacing typewriter whereby the tab stop setting blade is provided with a laterally extending operating head which has an efiective width which is only slightly less than the distance between adjacent tab stops but greater than the distance of two incremental units of travel of the carriage permitted by the proportional escapement mechanism, whereby a given tab stop may be set by said blade when the carriage is in different incremental positions.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same become better understood by reference to the following detailed description when considered in connection with the accompanying drawing in which like reference numerals designate like parts throughout the figure thereof and wherein the figure is a rear elevational view of the pertinent portions of the typewriter tab stop setting arrangement.

Referring to the drawing there is shown two successive tab stops and 11 which are operatively mounted in This aligning atent T 2,946,422 --Patented July 26,1960

the usual manner on the typewriter carriage 12. A conventionally supported and actuated tab set blade 14 is arranged to selectively displace the tab stops to their respective operative or set positions. In typewriters having escapement mechanisms which permitthe carriage operatively aligned with one of the carriage tab stops.

This situation is altered however when using a proportional escapement mechanism in the typewriter whereby the carriage may be differentially moved through oneor more small or fine incremental units of distance 15 in accordance with'the'respective widths of the'char-- :Yaeters typed. Here the respective tab stops are still uniformly; conventionally mounted as before but now will be coarsely spaced in terms of even multiples of the finely spaced positions possible for the typewriter carriage so that said tab stopssuccessively become aligned with the tab set blade only for every second or third consecutive incremental position of the carriage. If, for example, the coarsely spaced positions of the tab stops correspond to every third incremental carriage position, as shown in the figure, it will be evident that at any given time the print receiving position of the carriage may be such that the-tab stop 10 may be in position 10', 10" or the solid line position illustrated. If the tab stop 10 were in the central position 10" then it would be properly aligned with and could be operatively set by the usual type of tab set blade; however if said stop were in position 10' or in the solid line position shown then operation of the usual tab set blade would fail to displace the now misaligned stop 10 to its carriage arresting position. Corresponding conditions will exist for any of the other tab stops. In order to overcome this difficulty the instant invention contemplates provision of a laterally extending head 16 for the tab stop setting blade. The head 16 has a predetermined width W which is less than the distance between the adjacent sides of two successive tab stops but is at least as much as the combined length of that whole number of said incremental units 15 of carriage movement which is one less than the number of said units between two adjacent tab stops. In the apparatus shown then the width of head 16 is less than three but at least equal to two of said incremental units 15.

By providing such a head at the operative end of the tab blade 14 there will always be one and only one tab stop which is located so as to be moved to set position by operation of the tab stop setting blade and this condition will exist for any print receiving position possible for the typewriter carriage. Thus when it is desired to establish a tab position for the carriage, the typist simply moves the carriage to a desired tab position and operates the tab stop setting mechanism in the usual manner, there being no need of dealing with the above noted tedious and bothersome problem of successively aligning the tab stops to be set with the tab setting blade.

While there is in this application specifically described one form which the invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration only and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

The invention claimed is:

1. In a proportional spacing typewriter having a frame; a carriage movably mounted on said frame; a plurality of settable tab stops and a tab stop setting member, said stops and member being one on said frame and the other on said carriage: the improvement comprising a laterally extending head formed on said member and adapted to less than the number of said units-between two adjacent tab stops.

2. Apparatus as defined by claim 1 wherein the first mentioned number is equal to, two.

3;; In a proportional spacing typewriter having a framei a carriage movably mounted on said frame; aplurality of "settable tab stops and a tabstop setting member, saidstops] and member being one on saicl frarne: and the other on said carriage: the improvement com-prisinga laterally extending head formed on said member and adapted to selectively set said tab stops, said head having a width which is less than the distance between two adjacent tab stops but at least as great as-the length ofthat whole number of incremental units of carriage travel which is next less than the number of said units between said two adjacent stops. 1

4 121 a typewriter having a frame; a carriage slidably mounted on said frame; a plurality of uniformly spaced settable tab stops mounted on said carriage; a tab stop setting blade movably mounted on said frame and adapted to cooperate with said tab stops; and an escapement mechanism permitting said carriage to differentially move through a variable number of incremental units of distance in accordance with the respective widths of the characters typed, said tab stops having relative spaced positions which substantially correspond to three of said incremental units: the improvement comprising a head formed on said tabsetting blade and adapted to selectively engage and operatively displace 'said tab stops to set positions, the effective Width of said head being less than three but greater than two of said incremental units.

References Cited in the tile of this patent "UNITED STATES PATENTS V Khalil a Oct. 1,1957 2,885,052 Toggenburger May 5, 1959 

